The Southeast has the fastest-growing Latino population in the United States and at the same time carries a disproportionate HIV burden. Few efficacious HIV prevention interventions exist for either Latinos or men who have sex with men (MSM), and none exists for recently arrived, Spanish-speaking, less-acculturated Latino MSM. In response to PA-08-074 "Community Participation in Research," our community-university partnership proposes to jointly conduct a 5-year quasi-experimental study (R01) to refine, fully implement, and rigorously evaluate a lay health advisor (LHA) intervention designed to increase condom use and HIV testing among recently arrived, Spanish-speaking, less-acculturated Latino MSM who are settling in the rural Southeast. The intervention is based on social cognitive theory and theory of empowerment education and was developed using community-based participatory research (CBPR). This study is a result of a long-term community- university partnership that has used and will continue to use CBPR throughout all phases of research. A total of 20 Latino MSM in rural NC will be screened and recruited to serve as LHAs. Our partnership will select LHAs based on qualities of natural helpers and informal leaders and having existing social networks of other Latino MSM. Twelve members of each LHA's social network will be screened and recruited to participate as well. The LHAs, coupled with their social networks, will be randomized to intervention or delayed- intervention groups. LHAs (n=10) in the intervention group will be trained and serve as LHAs within their social networks in Year 2. Delayed-intervention LHAs (n=10) will receive the same LHA training and serve as LHAs within their social networks in Year 3. Quantitative assessment data will be collected from each LHA (n=20) and the 12 members of his social network (n=240) longitudinally at: (1) baseline, (2) immediate post- intervention, and (3) 12-month follow-up. This is an "intent-to-treat" study, in which participant data are analyzed based on their randomization group. We hypothesize that participants in the HIV prevention intervention, relative to those in the delayed- intervention comparison group, will demonstrate (1) increased self-reported use of condoms during sexual intercourse and (2) increased self-reported HIV testing. The results and products from this study will be disseminated to inform public health practice, research, and policy. Results and products will include: (1) a Spanish-language intervention that is: culturally relevant and gender-specific;designed to reduce HIV risk among Latino MSM;and ready for dissemination and adaptation;(2) a deeper understanding of HIV risk and intervention among Latino MSM;and (3) insight into a CBPR process that includes community members, organizational representatives, and academic researchers. PUBLIC HEALTH RELEVANCE: Few efficacious HIV prevention interventions exist for either Latinos or men who have sex with men (MSM), and none exists for recently arrived, Spanish-speaking, less-acculturated Latino MSM. Our community-based participatory research (CBPR) partnership proposes to refine, fully implement, and rigorously evaluate the effectiveness of a culturally relevant intervention designed to reduce the disproportionate HIV burden borne by Latino MSM in the United States (US).